Holloway scored a power-play goal in Tuesday's 8-1 loss to the Senators.
The 23-year-old spoiled a shutout bid for Linus Ullmark in the third period. Holloway has scored three goals, two with the man advantage, in three games since Robert Thomas (ankle) was injured, and the former Oiler could be building a case for a more prominent spot on the depth chart even when the Blues' roster is at full strength.